[9] On a train ride through Europe, a young woman (Margaret Lockwood) discovers a fellow passenger (Dame May Whitty) has gone missing. No one remembers seeing the old woman, not even the people who shared a cabin with them. A rogue musicologist (Michael Redgrave) is sympathetic to Lockwood’s dilemma, and together they uncover a conspiracy behind the woman’s disappearance. But will they be able to …